Sub-surface fluorescence time-of-flight imaging using a large format SPAD sensor

Classical fluorescence guided surgery uses long laser pulses to excite fluorescent tracers, only providing the practitioner with 2D information. In this work, we develop and test a 3D imaging technique using LiDAR technology to sense target tissue depths up to 5 mm below the surface. Imaging through highly scattering medium like tissues implies that temporal information used for 3D reconstruction is convolved with diffuse dynamics of the medium. Using diffuse reflectance as an indicator of the medium’s optical properties, correction of the time-of-flight is made possible. Time-of-flight fluorescence imaging, captures intensity as well as temporal profile of fluorescence excited by ultra-short pulses.